


Kitty's Kinktober 2019

by Epic_and_Kitty



Category: Undertale (Video Game)
Genre: Ecto-Genitalia (Undertale), Ecto-Penis (Undertale), Ecto-Tongue (Undertale), Established Relationship, F/M, First Time, Kinktober 2019, Plot What Plot/Porn Without Plot, Porn With Plot, Porn with Feelings, Reader is a tsundere, Scent Kink, Tags to be added as needed, Tsunderes, Underlust, and they were ROOMMATES, implied demisexual reader, oh my god they were roommates, tsundere's are fun to write
Language: English
Status: In-Progress
Published: 2019-10-06
Updated: 2019-10-06
Packaged: 2020-11-25 18:42:16
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,489
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/20916767
Author URL: https://archiveofourown.org/users/Epic_and_Kitty/pseuds/Epic_and_Kitty
Summary: My attempt at doing kinktober five days late. You wanted Succubus Blues? TOO BAD SEX ONE SHOT TIME. Will include my own Undertale OCs and possibly reference my big fic (no spoilers, these one shots are not related to the plot of Succubus Blues). Probably will be more fluff than sex to be honest. I'm using my own prompts!





	Kitty's Kinktober 2019

**Author's Note:**

> Yo, welcome to chapter one of my attempt at kinktober! Dont expect all of the days fics to be this long, I kinda just rolled with this one. 
> 
> Prompt - First Time
> 
> Pairing - Underlust Sans/ Reader
> 
> Additional Kinks - scent kink, implied demisexual reader, tsundere, fluffy dorks in love
> 
> Comment and enjoy!

You take a deep breath and look towards the bathroom where you're roommate was taking a shower before bed, silently berating yourself.

You and him are dating now, this shouldn't be so hard to talk to him about!

But it was, considering, well everything!

Sans was way more experienced than you in intimacy. More to the point, he had actually had sex before, unlike your virgin self.

Hell, before you started dating, he had brought home a new person every night and they would fuck in his room.

Loudly.

At first, you thought your frustration was not getting any sleep until the wee hours of the night, and the first few years or so, it probably was that reason. But, slowly, you realized that it had gone past annoyance and had become jealousy. It didn't surprise you; you had been spending more time with him and developing a major crush on the skeleton. You were more scared than anything, afraid to ruin your friendship at worst or be shot down at the very least.

You shook yourself out of your reverie as the shower turned off and you could hear Sans humming just a door away. You could do this. It was just a few words. It was easy, stop psyching yourself out, you big weenie -!

"penny for your thoughts, love?"

You...You jump more than your willing to admit, resulting in you falling back onto the bed and scrambling to pull your nightshirt down before he saw the black lacy panties with the bright pink bows you were wearing as a surprise if you had gotten the guts to ask.

Judging by his expression, however, he had most definitely seen. The bastard!

You glare at him and puff out your cheeks.

"Asshole!"

"only when i have ecto, princess."

He chuckles as he crawls into bed next to you, poking your cheek with a smug expression. "you didn't answer my question, though. what's my little tsundere thinking?"

"I'm NOT a tsundere-!" You splutter angrily, just as Sans leans in to kiss you. Or more accurately, nuzzle his teeth against your lips. Whatever it was, you stop arguing and lean in, just a little though. You didn't want him to think you were enjoying it too much.

As he pulls back, chuckling (damned bastard!), he gives you a rare serious expression, gently holding your chin up.

"seriously though, pigeon, what's the matter? you know you can talk to me about anything."

You glance away and back again, seeing him smile softly at you, his eyelights soft white. You take a deep breath and gulp down your nerves before speaking softly.

"I-I've been thinking, a-and I think... I think I'm ready to go all the way with you tonight..."

You look back up at Sans, having had to look away for nerves sake, and startle a bit at his shocked expression and blank eyesockets. He quickly recovers, his eyelights becoming bright purple hearts. He pulls your chin closer, looking you in the eyes and refusing to let you look away.

"Are you sure, dove? Is that what you want?"

You nodd vigorously, not trusting your voice at the moment. He smiles wide, a bit of purple smoke leaking from his eye socket, before quickly blinking it away and looking at you seriously again.

"i'm gonna need verbal conformation, baby doll."

You stare wildly before managing to squeak out a "yes", which Sans thankfully takes, gently adjusting you to lie on your back as he looms over you, caressing your cheek and neck.

"you know you can say no at any time, right? just say 'stop' and I won't push."

You nod, giving a tense "yes". Sans chuckles softly, leaning down to kiss you. 

"hey, relax. it's ok. i'm here. and i love you, no matter what."

You blink, then nod softly, smiling up at him. "I know, Sans, I know."

He grins down at you, grabbing the hem of your nightshirt and kissing your neck. "i'll be gentle."

You gasp at kiss, regaining some of your fire to squawk "You damn well better be gentle, jerk-!"

You get cut off by your own moan as he strokes your pussy through your panties, embarrassingly wet already. Sans chuckles again, leaning back to gaze down at your body, hands drifting to stroke your nipples after pulling the nightshirt off completely.

"stars, you're so beautiful, love." You open your mouth to retort, only to moan loudly as he licks your nipple, hand drifting under your underwear hem to find your clit. He pulls part of your hem down before giving you a glance for permission. You nod furiously and he pulls them off before sitting back and admiring them closely.

"If this becomes a regular thing with us, you're going to have to keep these stocked cause damn they're cute. Though I thought virgins were supposed to wear white..."

He shot you a teasing grin, and before you could snark back at him, he brought the panties up to his nose to sniff them deeply. You blush deeply as he glances back down at you.

"W-weirdo..."

He only responds by tossing the panties away and grining wickedly. He quickly dives between your legs and starts sucking on your folds, his fingers teasing at your sensitive little bud. You jolt and squrim, grabbing his head and pushing him deeper between your legs.

"Oh fuck! Sans!"

His chuckles vibrate against you and you buck your hips into his face. He looks up at you as his tounge dips into your pussy. He groans deeply at your taste and eats you out in earnest. It only takes a few minutes under his minstrations before you orgasm hard, arching your back into his face. He pulls back, licking his teeth and slipping several fingers inside to stretch you out, grining wildly all the while.

"i'm gonna make you feel so good, baby girl." 

You whimper, weakly grabbing the hand teasing you and trying to steady it, feeling a little overwhelmed. Sans noticed, pulling away his hand away with a concerned frown.

"Sweetheart, do you need to stop?"

You shook your head as your body shivered from the after shock.

"I-I just need a breather, r-really over-senstive right now." You take a deep breath, looking away. "C-can you just hold me for a bit, pl-please?"

Sans smiled, grabbing you and pulling you on top of him, gently rubbing your back. You grin back at him, nuzzling under his chin contentedly. You stay that way for several minutes, in a comfortable silence, still occasionally shuddering from the aftershocks. Sans hands eventually drifted to your ass and squeezed, making you let out any indignant squawk.

"Hey-!"

"-is for horses, sugar."

You glare at him and he snickers.

"what? you expect me not to squeeze the cutest ass in existence?"

"My ass is not CUTE-!" You start, only for Sans to put a finger to your lips, smiling wildly and holding back giggles.

"trust me, dove, i, comic 'sans' gaster, am a professional. a butt lover. a gluteus maximus connoisseur, if you will. an ass man. an expert in all things bootylicious. and it is my expert opinion that you're money maker is, indeed, extremely cute."

You continue to glare at Sans as he tries to hold back his snickers.

"Fuck you!"

"oh so your ready to go again? you recover rather fast for a first timer!"

You start to squawk and stutter as Sans loses his battle with the giggles and starts guffawing. He brings you closer as you try to pull away, kissing you all over your face and chest inbetween his giggles and snorts. He gently grabs your face to try to get you to look at him, but you refuse to look him in the eyes.

"baby. baby. baby girl. sugar pie. look at me sweet pea. please. it's important."

You finally glare at him. "WHAT."

He gives you a genuine smile, all sign of giggles gone.

"i love you. so damn much. you know that right?"

You can't keep your glare, not with how genuine he's being, especially with how hard it is for him to push past all his walls. You lean up to kiss him.

"I know, Sans. I love you too."

His genuine smile makes you blush harder than when he was eating you out, so you hide your face in his chest. He pets your head before coaxing you to look at him again.

"we don't have to go all the way if you're too tired or nervous. we can just cuddle and go to bed. i'm open to whatever and won't push you into it either way."

You smile and shake your head.

"It's ok, Sans, I'm ready to continue if you are."

Sans snorts and rolls you on your back again, straddling you.

"'if you are.'" He rolls his eyelights before looking back at you with a smirk. "that's my secret, captain." He leans over to whisper in your ear.

"I'm always ready."

You can't help yourself as you snort at the dumb meme, and he kisses your neck before leaning back up to get something from the nightstand. He sits up and messes with the bottle of lube and as he does so, you see his girthy purple cock resting on your thigh. He catches you looking at it and wiggles his hips, making it sway side to side.

"Like what you see, love?"

You gulp and nod, trying not to think to hard about how it would fit. Almost as if reading mind, Sans gave you a comforting smile and stroked your cheek softly.

"that's what the lube is for, sweetie. i'll be gentle with you, don't worry."

You nod in understanding, then jolt as he globs lube over your folds. He glances up at you in concern. You chuckle awkwardly.

"It's really cold, heh..."

He smiles leans in as he massages it into you, whispering in your ear again.

"don't worry, it'll warm up once we start fucking."

You gulp and blush as he chuckles, leaning back up to dig in the nightstand one handedly, quickly pulling out a condom. You open your mouth as he rips it open and puts it on with a surprising amount of expertise. He sees the question on your face and answers before you can find the words.

"usually, unless we were to share SOULS, i'd be unable to impregnate you, but my heat starts later this month, so better safe than sorry." He grins smugly at you.

"there will be plenty of times after this if you want to ride my dick bare boned."

You groan loudly as Sans starts snickering again.

"That pun was bad and you should feel bad."

He laughed, nuzzling into your neck again.

"you know you loved it."

He let out a little gasp as he rubbed lube over his cock, leaning up to look at you with the most lustful expression you had seen from him.

"you ready, baby girl?"

You gulp and nod.

"As I'll ever be."

He kisses your neck, whispering against your skin.

"i'll be gentle, you're in charge of how much you want, so don't be afraid to ask, ok?"

"Ok." 

He grins and lines himself up with your folds before pushing forward slowly, gasping as the head if his cock enters you.

"holy shit. oh gods."

You whimper as he pushes forward, gripping his arms for support. He takes his time, pausing whenever he meets resistance to pull back and push forward again. Several minutes of gentle pushing in and out go by before he hilts inside you.

"stars you feel amazing. how you holding up, sweetheart?"

You adjust yourself a bit, enjoying his gasps as you inadvertently squeeze him.

"I...I think I'm good."

"you need a few minutes, baby doll?"

You shake your head and move your arms to grip his back.

"No, I think I'm good, baby. Go right ahead."

Sans lets a shuddering breath before nodding and starting to move slowly, almost pulling all the way out before thrusting slowly back in. You groan loudly as he starts his pace, hooking your legs around his pelvis to keep him closer. You both groan at the change in angle, thrusting your own hips in time with his thrusts.

"Sans, please, fuck! Faster!"

Sans growls and speeds up at your request, biting back his grunts and moans. You feel a fire in your belly as he speeds up his pace. You reach down to rub your clit, but Sans smacks it away to stroke your nub instead.

"i'm - fuck! - i'm the one in charge of your pleasure, baby girl, just let me make you feel good, ok?"

You nod, your voice having long failed you. You buck into him to urge him faster, and faster he goes. The fire in your belly is growing, coiling and almost ready to snap. Sans feels your orgasm coming and chuckles breathlessly.

"you gonna come, baby? come with me then! just hold a litt-"

You can't hold it back, coming hard as he only now starts to reach the peak. He keeps going, holding you tightly, trying his best to reach his end in your aftershocks. Only a few seconds after your climax ends, he comes hard inside you with a cry of your name, all of it being caught inside the condom.

He gasps above you before collapsing on top of you, still recovering from his own climax. He pulls back to look at you with literal stars in his eyes before kissing you soundly.

"stars, love, you were amazing!" He nuzzles into your neck and you can feel his smile against your skin. "thank you for letting me be your first."

Leaning back up to look at you, he strokes your cheek.

"did you enjoy yourself, pigeon?"

You giggle and nod, hugging him closer.

"Yes, thank you." You kiss him on his teeth and both of you break into giggles and nuzzle into each other.

"stars i love you."

"I love you too, Sans." You groan a bit as he pulls out, feeling empty. He pulls off the condom and ties it off before throwing it in the trash. You startle a bit as he picks you up off the bed, and he snorts as you grab onto him.

"what? i got ya dirty, now i gotta clean you up."

He winks at you and you pout as your blush deepens. An idea strikes you and you lean up to whisper in his ear.

"You know, I wouldn't mind if you got me pregnant next time."

He staggers a bit, but rights himself soon enough.

"we'll talk about that later, when your not high on sex, baby girl."

You grin a bit at his barely masked warbling voice. You rest your head on his chest, dozing with a grin on your face.

Little did he know, you are completely serious.

**Author's Note:**

> * It's Not Like I Like You playing softly in the distance*
> 
> Please leave a comment! They feed my motivation!


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